During the summer, ski resorts provide a ride down a mountain on a track using a sled. The track typically consists of an assembly of prefabricated sections having a variety of different curves and straight sections. The track is designed and installed to conform to the terrain of the mountain and may vary from 1000 to 5000 feet in length depending on the vertical drop between the start and finish. The tracks are usually installed on a roadbed, in ground, with a pitch varying from, for example, 10 to 22 percent. The track may also be a road, path or other terrain having a pitch or slope.
Conventional sleds use runners for gliding, wheels for providing acceleration and rubber strips for braking. Each sled is designed to carry one rider that controls the speed of the sled using a control stick. The control stick provides acceleration—by moving the stick forward, gliding—by moving the stick to a middle position, and braking—by moving the stick to a rear position.
A track having a high pitch, such as, for example, 16-22 percent, typically uses a sled with front wheels attached to the control stick and runners. As the control stick is moved forward, the wheels lift a portion of the sled chassis away from the track, causing less friction by the runners on the track. A track having a lower pitch, such as, for example, 10-15 percent, typically uses a sled having front and rear wheels and runners. The rear wheels are necessary on lower pitch tracks because of the friction generated by the runners on the track, e.g. the sled would not make it down the track otherwise. Rear wheels are not provided for conventional sleds used on higher pitched tracks because the sled would gain too much speed. A sled without rear wheels, however, will “fishtail”, while a sled with rear wheels will not. Therefore, a sled with rear wheels is more stable and less susceptible to accidents, but not usable on a higher pitch tracks because it causes the sled to travel too fast.
As expected, some riders drive too fast down the track, which sometimes results in accidents causing injury. The accidents are usually caused by excess speed causing the rider to fall off the sled and land on the track or, in some cases, to leave the track. When injuries occur, they are usually minor, consisting of scrapes and bruises, but may result in broken bones. However, such injuries are an annoyance to the track operators and can result, from time to time, in lawsuits.